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  • Author or Editor: Kenneth C. Thomas x
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Kenneth C. Thomas, Christopher S. Bailey, Marcel F. Dvorak, Brian Kwon and Charles Fisher

Object

Despite extensive published research on thoracolumbar burst fractures, controversy still surrounds which is the most appropriate treatment. The objective of this study was to evaluate the scientific literature on operative and nonoperative treatment of patients with thoracolumbar burst fractures and no neurological deficit.

Methods

In their search of the literature, the authors identified all possible relevant studies concerning thoracolumbar burst fracture without neurological deficit. Two independent observers performed study selection, methodological quality assessment, and data extraction in a blinded and objective manner for all papers identified during the search. In a synthesis of the literature, the authors obtained evidence for both operative and nonoperative treatments.

Conclusions

There is a lack of evidence demonstrating the superiority of one approach over the other as measured using generic and disease-specific health-related quality of life scales. There is no scientific evidence linking posttraumatic kyphosis to clinical outcomes. The authors found that there is a strong need for improved clinical research methodology to be applied to this patient population.

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Matthew J. McGirt, Ketan R. Bulsara, Thomas J. Cummings, Kent C. New, Kenneth M. Little, Henry S. Friedman and Allan H. Friedman

Object. The prognostic value of differentiating between recurrent malignant glioma and a lesion due to radiation effect by performing stereotactic biopsy has not been assessed. Thus, this study was undertaken to determine such value.

Methods. Between 1995 and 2001, 114 patients underwent magnetic resonance (MR) imaging—guided stereotactic biopsy to differentiate lesions caused by a recurrence of malignant astrocytoma and by radiation effect. All patients had previously undergone tumor resection (World Health Organization Grade III or IV) followed by radiotherapy. Disease diagnosis based on biopsy and patient characteristics were assessed as predictors of survival according to results of a multivariate Cox regression analysis. The diagnosis determined with the aid of biopsy was compared with that established during a subsequent resection in 26 patients.

Survival following stereotactic biopsy was markedly increased in patients suffering from radiation effect compared with those harboring recurrent malignant glioma (p < 0.0001). In patients with radiation effect on biopsy, an increasing patient age (p < 0.05), having had two compared with one prior resection (p < 0.05), and a decreasing time from radiotherapy to biopsy (p < 0.001) were factors associated with decreased survival. Nevertheless, in patients with biopsy-defined radiation effect at second progression or with an age younger than 50 years the survival rate remained higher than that in patients with recurrent tumor on biopsy (p < 0.01). A biopsy-based diagnosis of radiation effect obtained less than 5 months after radiotherapy was not associated with an increased rate of patient survival compared with a diagnosis of recurrent malignant glioma on biopsy (p = 0.286). Eighty-six percent of lesions initially determined to be due to radiation effect on biopsy fewer than 5 months after radiotherapy were characterized as recurrent glioma by a mean of 11 months later. In contrast, only 25% of lesions initially diagnosed as attributable to radiation effect on biopsy more than 5 months after radiotherapy were classified as recurrent glioma a mean of 12 months later (p < 0.05).

Conclusions. With the aid of stereotactic biopsy the authors demonstrated prognostic significance in differentiating recurrent malignant astrocytoma from a lesion due to radiation effect in patients presenting more than 5 months after having undergone radiotherapy. In patients who presented earlier than 5 months after radiotherapy, radiation effect on biopsy was not associated with an improved rate of survival compared with that in patients harboring recurrent malignant astrocytoma.

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Shabbar F. Danish and Paul J. Marcotte

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Praveen V. Mummaneni, J. Kenneth Burkus, Regis W. Haid, Vincent C. Traynelis and Thomas A. Zdeblick

Object

The authors report the results of a prospective randomized multicenter study in which the results of cervical disc arthroplasty were compared with anterior cervical discectomy and fusion (ACDF) in patients treated for symptomatic single-level cervical degenerative disc disease (DDD).

Methods

Five hundred forty-one patients with single-level cervical DDD and radiculopathy were enrolled at 32 sites and randomly assigned to one of two treatment groups: 276 patients in the investigational group underwent anterior cervical discectomy and decompression and arthroplasty with the PRESTIGE ST Cervical Disc System (Medtronic Sofamor Danek); 265 patients in the control group underwent decompressive ACDF. Eighty percent of the arthroplasty-treated patients (223 of 276) and 75% of the control patients (198 of 265) completed clinical and radiographic follow-up examinations at routine intervals for 2 years after surgery.

Analysis of all currently available postoperative 12- and 24-month data indicated a two-point greater improvement in the neck disability index score in the investigational group than the control group. The arthroplasty group also had a statistically significant higher rate of neurological success (p = 0.005) as well as a lower rate of secondary revision surgeries (p = 0.0277) and supplemental fixation (p = 0.0031). The mean improvement in the 36-Item Short Form Health Survey Physical Component Summary scores was greater in the investigational group at 12 and 24 months, as was relief of neck pain. The patients in the investigational group returned to work 16 days sooner than those in the control group, and the rate of adjacent-segment reoperation was significantly lower in the investigational group as well (p = 0.0492, log-rank test). The cervical disc implant maintained segmental sagittal angular motion averaging more than 7°. In the investigational group, there were no cases of implant failure or migration.

Conclusions

The PRESTIGE ST Cervical Disc System maintained physiological segmental motion at 24 months after implantation and was associated with improved neurological success, improved clinical outcomes, and a reduced rate of secondary surgeries compared with ACDF.

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Thomas J. Buell, Daniel M. S. Raper, I. Jonathan Pomeraniec, Dale Ding, Ching-Jen Chen, Davis G. Taylor and Kenneth C. Liu

Stenosis of the transverse sinus (TS) and sigmoid sinus (SS), with a trans-stenosis pressure gradient, has been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH). MRI has shown improvement in TS and SS stenosis after high-volume lumbar puncture (HVLP) in a subset of patients with IIH. The authors present the first report of an IIH patient with immediate post-HVLP TS and SS trans-stenosis pressure gradient reduction and an attendant increase in TS and SS cross-sectional area confirmed using intravascular ultrasonography (IVUS). Recurrence of the patient’s TS-SS stenosis coincided with elevated HVLP opening pressure, and venous sinus stent placement resulted in clinical improvement. This report suggests that TS and SS stenosis may be a downstream effect of elevated intracranial pressure in IIH, rather than its principal etiological mechanism. However, the authors hypothesize that endovascular stenting may obliterate a positive feedback loop involving trans-stenosis pressure gradients, and still benefit appropriately selected patients.

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Lawrence F. Marshall

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Guy L. Clifton, Sung C. Choi, Emmy R. Miller, Harvey S. Levin, Kenneth R. Smith Jr., J. Paul Muizelaar, Franklin C. Wagner Jr., Donald W. Marion and Thomas G. Luerssen

Object. In a recently conducted trial of hypothermia in patients with severe brain injury, differences were found in the effects of hypothermia treatment among various centers. This analysis explores the reasons for such differences.

Methods. The authors reviewed data obtained in 392 patients treated for severe brain injury. Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers. Hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age in whom hypothermia was present on admission, and without effect in those in whom normothermia was documented on admission. Marginally significant differences (p < 0.054) in the intercenter outcomes of hypothermia-treated patients were likely the result of wide differences in the percentage of patients older than 45 years of age and in the percentage of patients in whom hypothermia was present on admission among centers. The trial sensitivity was likely diminished by significant differences in the incidence of mean arterial blood pressure (MABP) less than 70 mm Hg (p < 0.001) and cerebral perfusion pressure (CPP) less than 50 mm Hg (p < 0.05) but not intracranial pressure (ICP) greater than 25 mm Hg (not significant) among patients in the various centers. Hours of vasopressor usage (p < 0.03) and morphine dose (p < 0.001) and the percentage of dehydrated patients varied significantly among centers (p < 0.001). The participation of small centers increased intercenter variance and diminished the quality of data.

Conclusions. For Phase III clinical trials we recommend: 1) a detailed protocol specifying fluid and MABP, ICP, and CPP management; 2) continuous monitoring of protocol compliance; 3) a run-in period for new centers to test accrual and protocol adherence; and 4) inclusion of only centers in which patients are regularly randomized.

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Christopher S. Bailey, Marcel F. Dvorak, Kenneth C. Thomas, Michael C. Boyd, Scott Paquett, Brian K. Kwon, John France, Kevin R. Gurr, Stewart I. Bailey and Charles G. Fisher

Object

The authors compared the outcome of patients with thoracolumbar burst fractures treated with and without a thoracolumbosacral orthosis (TLSO).

Methods

As of June 2002, all consecutive patients satisfying the following inclusion criteria were considered eligible for this study: 1) the presence of an AO Classification Type A3 burst fractures between T-11 and L-3, 2) skeletal maturity and age < 60 years, 3) admission within 72 hours of injury, 4) initial kyphotic deformity < 35°, and 5) no neurological deficit. The study was designed as a multicenter prospective randomized clinical equivalence trial. The primary outcome measure was the score based on the Roland-Morris Disability Questionnaire assessed at 3 months postinjury. Secondary outcomes are assessed until 2 years of follow-up have been reached, and these domains included pain, functional outcome and generic health-related quality of life, sagittal alignment, length of hospital stay, and complications. Patients in whom no orthotic was used were encouraged to ambulate immediately following randomization, maintaining “neutral spinal alignment” for 8 weeks. The patients in the TLSO group began being weaned from the brace at 8 weeks over a 2-week period.

Results

Sixty-nine patients were followed to the primary outcome time point, and 47 were followed for up to 1 year. No significant difference was found between treatment groups for any outcome measure at any stage in the follow-up period. There were 4 failures requiring surgical intervention, 3 in the TLSO group and 1 in the non-TLSO group.

Conclusions

This interim analysis found equivalence between treatment with a TLSO and no orthosis for thoracolumbar AO Type A3 burst fractures. The influence of a brace on early pain control and function and on long-term 1- and 2-year outcomes remains to be determined. However, the authors contend that a thoracolumbar burst fracture, in exclusion of an associated posterior ligamentous complex injury, is inherently a very stable injury and may not require a brace.

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Nathan Evaniew, David W. Cadotte, Nicolas Dea, Christopher S. Bailey, Sean D. Christie, Charles G. Fisher, Jerome Paquet, Alex Soroceanu, Kenneth C. Thomas, Y. Raja Rampersaud, Neil A. Manson, Michael Johnson, Andrew Nataraj, Hamilton Hall, Greg McIntosh and W. Bradley Jacobs

OBJECTIVE

Recently identified prognostic variables among patients undergoing surgery for cervical spondylotic myelopathy (CSM) are limited to two large international data sets. To optimally inform shared clinical decision-making, the authors evaluated which preoperative clinical factors are significantly associated with improvement on the modified Japanese Orthopaedic Association (mJOA) scale by at least the minimum clinically important difference (MCID) 12 months after surgery, among patients from the Canadian Spine Outcomes and Research Network (CSORN).

METHODS

The authors performed an observational cohort study with data that were prospectively collected from CSM patients at 7 centers between 2015 and 2017. Candidate variables were tested using univariable and multiple binomial logistic regression, and multiple sensitivity analyses were performed to test assumptions about the nature of the statistical models. Validated mJOA MCIDs were implemented that varied according to baseline CSM severity.

RESULTS

Among 205 patients with CSM, there were 64 (31%) classified as mild, 86 (42%) as moderate, and 55 (27%) as severe. Overall, 52% of patients achieved MCID and the mean change in mJOA score at 12 months after surgery was 1.7 ± 2.6 points (p < 0.01), but the subgroup of patients with mild CSM did not significantly improve (mean change 0.1 ± 1.9 points, p = 0.8). Univariate analyses failed to identify significant associations between achieving MCID and sex, BMI, living status, education, smoking, disability claims, or number of comorbidities. After adjustment for potential confounders, the odds of achieving MCID were significantly reduced with older age (OR 0.7 per decade, 95% CI 0.5–0.9, p < 0.01) and higher baseline mJOA score (OR 0.8 per point, 95% CI 0.7–0.9, p < 0.01). The effects of symptom duration (OR 1.0 per additional month, 95% CI 0.9–1.0, p = 0.2) and smoking (OR 0.4, 95% CI 0.2–1.0, p = 0.06) were not statistically significant.

CONCLUSIONS

Surgery is effective at halting the progression of functional decline with CSM, and approximately half of all patients achieve the MCID. Data from the CSORN confirmed that older age is independently associated with poorer outcomes, but novel findings include that patients with milder CSM did not experience meaningful improvement, and that symptom duration and smoking were not important. These findings support a nuanced approach to shared decision-making that acknowledges some prognostic uncertainty when weighing the various risks, benefits, and alternatives to surgical treatment.